Gulf of California Deglacial Biogenic SST Reconstructions McClymont, E.L.; Ganeshram, R.S.; Pichevin, L.; Talbot, H.M.; van Dongen, B.E.; Thunell, R.C.; Haywood, A.M.; Singarayer, J.S.; Valdes, P.J. McClymont, E.L. Ganeshram, R.S. Pichevin, L. Talbot, H.M. van Dongen, B.E. Thunell, R.C. Haywood, A.M. Singarayer, J.S. Valdes, P.J. Sea Surface Temperature Reconstruction earth science/paleoclimate/paleoceanography (biogenic silica,sediment,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleoceanography (sea surface temperature,glycerol dialkyl glycerol tetraether index,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,based on TEX86) earth science/paleoclimate/paleoceanography (tetraether index of 86 carbon atoms,null,null,dimensionless,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,calendar year before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleoceanography (sea surface temperature,alkenone unsaturation index|glycerol dialkyl glycerol tetraether index,null,degree Celsius,null,climate reconstructions|paleoceanography,differenced,null,N,UK37 - TEX86) earth science/paleoclimate/climate reconstructions|paleoceanography (sea surface temperature,alkenone unsaturation index,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (alkenone unsaturation index Uk37 prime,null,null,dimensionless,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (branched and isoprenoid tetraether index,null,null,dimensionless,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (branched glycerol dialkyl glycerol tetraether,null,null,milligram per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (MD02-2515>LATITUDE 27.4835>LONGITUDE -112.0743) Centennial-scale records of sea-surface temperature and opal composition spanning the Last Glacial Maximum and Termination 1 (circa 25-6 ka) are presented here from Guaymas Basin in the Gulf of California. Through the application of two organic geochemistry proxies, the UK37'index and the TEX86H index, we present evidence for rapid, stepped changes in temperatures during deglaciation. These occur in both temperature proxies at 13 ka (~3°C increase in 270 years), 10.0 ka (~2°C decrease over ~250 years) and at 8.2 ka (3°C increase in <200 years). An additional rapid warming step is also observed in TEX86H at 11.5 ka. In comparing the two temperature proxies and opal content, we consider the potential for upwelling intensity to be recorded and link this millennial-scale variability to shifting Intertropical Convergence Zone position and variations in the strength of the Subtropical High. The onset of the deglacial warming from 17 to 18 ka is comparable to a "southern hemisphere" signal, although the opal record mimics the ice-rafting events of the north Atlantic (Heinrich events). Neither the modern seasonal cycle nor El Niño/Southern Oscillation patterns provide valid analogues for the trends we observe in comparison with other regional records. Fully coupled climate model simulations confirm this result, and in combination we question whether the seasonal or interannual climate variations of the modern climate are valid analogues for the glacial and deglacial tropical Pacific. STUDY NOTES: Sea surface temperature (SST) reconstructions for the Gulf of California (GOC) based on two organic geochemical proxies, the UK37'index and the TEX86H index. Data cover the deglacial interval from roughly 25 - 6 ka. Giant Calypso core MD02-2515 was collected from Guaymas Basin in the central GOC during the 2002 IMAGES-MONA expedition Core MD02-2515: 27°29.01'N, 112°04.46'W, 881 m water depth. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : McClymont, E.L. Investigator : Ganeshram, R.S. Investigator : Pichevin, L. Investigator : Talbot, H.M. Investigator : van Dongen, B.E. Investigator : Thunell, R.C. Investigator : Haywood, A.M. Investigator : Singarayer, J.S. Investigator : Valdes, P.J. 2012-08-13 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/13280 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/mcclymont2012/mcclymont2012.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/mcclymont2012/mcclymont2012.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/mcclymont2012/mcclymont2012.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/mcclymont2012/mcclymont2012.txt English https://www.ncdc.noaa.gov/paleo/study/13280 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/mcclymont2012/mcclymont2012.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/mcclymont2012/mcclymont2012.txt McClymont, E.L., R.S. Ganeshram, L.E. Pichevin, H.M. Talbot, B.E. van Dongen, R.C. Thunell, A.M. Haywood, J.S. Singarayer, and P.J. Valdes. 2012. Sea-surface temperature records of Termination 1 in the Gulf of California: Challenges for seasonal and interannual analogues of tropical Pacific climate change. Paleoceanography, 27, PA2202, doi:10.1029/2011PA002226 START YEAR: 24988 cal yr BP * END YEAR: 6825 cal yr BP -112.0743 27.4835 -112.0743 27.4835